noun
Primarily refers to the silkworm cocoon used in silk production, but can also refer to other insect cocoons.
蚕が繭を作り始めた。
The silkworms have started spinning cocoons.
繭から絹糸を取る。
Silk thread is taken from the cocoon.
蚕 is the silkworm itself, while 繭 is the cocoon it produces.
蛹 is the pupa inside the cocoon; 繭 is the protective casing.
The kanji 繭 is a phono-semantic compound, combining 糸 (thread) and a phonetic element. The reading まゆ is native Japanese.